Configure the Link Characteristics

By default, the router's management Ethernet interface, fxp0, autonegotiates whether to operate in full-duplex or half-duplex mode. Fast Ethernet interfaces can operate in either full-duplex or half-duplex mode, and all other interfaces can operate only in full-duplex mode. For Gigabit Ethernet, the link partner must also be set to full duplex.

To explicitly configure an Ethernet interface to operate in either full-duplex or half-duplex mode, include the link-mode statement at the [edit interfaces interface-name] hierarchy level:

[edit interfaces interface-name]

link-mode (full-duplex | half-duplex);